Inside Cho's Mind

After months of investigation into the shootings at Virginia Tech, Gov. Tim Kaine of Virginia released a much anticipated report this morning by a panel of experts he convened.

The bottom line: The killer, Seung Hui Cho, had been mentally ill since childhood. Over the years, his family and others had gotten him help -- including counseling and medication. But when Cho arrived at Virginia Tech, the systems failed.

Molly Donohue lived in West Ambler Johnston Hall, the dormitory where Cho's shooting spree began. "A little before 7:15, I heard a really loud female voice scream … and then I heard two very, very loud poundings again. It sounded like they were against the cement wall," Donohue told ABC News. "And then I heard another scream and I heard more poundings and this is all happening very on top of each other and all at once."

In her first television interview since the shootings, Blacksburg Police Chief Kim Crannis and members of her department sat down with "Nightline" to explain how the police department responded to the Cho shootings.

According to Crannis, the police department "got a call of a subject who they thought had fallen out of the bed."

"Once the first responding officer got there, he realized there was more to it than that," Crannis said.

After hearing the initial noise outside her door, Donohue explained what she saw. "I opened my door and that's when I saw the blood and the footprints, the sneaker prints leading in a trail from her room, and just leading away from everything… and that's when I saw, at the time I didn't know it was my [Resident Assistant Ryan Clark] and we called him 'Stack.'"

"This is what we know: we've got one male that's dead, we got one female that's clinging to life that's being airlifted to a central Virginia trauma center, and the shooter's loose," Capt. Bruce Bradbery of the Blacksburg Police Department told "Nightline." "You assume in a situation like that you're going to wrap this thing up pretty quickly, hope that you can."

But even after the deaths of Emily Hilscher and Ryan Clark at West Ambler Johnston Hall, it was far from over. What no one knew, what no one imagined, was that the killing at Virginia Tech had only just begun. Across campus, a dangerously disturbed young man was methodically readying his final act -- a killing spree that would leave the entire country stunned by its sheer scale and brutality.

The story begins far away form Virginia, in another country, another culture.

Cho's Early Years

Cho was born in Seoul, South Korea, in 1984. Some of his extended family still lives there, including his maternal grandfather, Hyang-Sik Kim, who said the Cho family today is shattered. Kim spoke exclusively with "Nightline."

"I got a call from my daughter almost a month after the shooting," said Kim. "She said she was calling from outside. All she said was, 'Is that you, father?' And then it was an ocean of tears."

While in Seoul, the Cho family ran a used bookstore and made little money doing it. Cho lived with his parents and his older sister Sun-Kyung Cho in a basement apartment.